M30B32 + carbs?

HB Chris

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Post a pic of underside of head, are the two shallow dimples still present on intake side? If not it has been cut to minimum thickness. If they are there and you keep it, take it to a machinist to pressure test for cracks, if good then clean up valves, replace any bad valve guides and all valve stem seals. If you go b35 then use the b35 head as ports are larger and it has dual valve springs. The loose oil pipe screw might still be okay, if it fell off you would lose oil to the cam and rockers.
 
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bmw2800cs

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As to fuel pump, the head on the M30b32 likely won't have a place to mount it. You will need to install an electric pump. I suggest looking at this thread: https://e9coupe.com/forum/threads/adding-a-electric-fuel-pump-suggestions.42221/post-369474

I think you need this nut to mount that distrubutor drive gear to the cam in your motor: https://www.ecstuning.com/b-genuine-bmw-parts/hex-nut/11311284801/ Double check this with Don Lawrence (sfdon).

As to carburetors, I think you have a couple of options. First, you could perhaps rebuild the Zeniths you have, but they don't look great.

Second, you could hunt down a set of Zeniths that are in good shape. Loks of people took these off their cars, so there are probably some around. I gave away a pair last year. If you go this route, however, you probably want to hunt down the BMW tuning data for the 3.3L, which used the M30b32. Zeniths tuned for a M30b30 may not work well on a M30b32.

Then there are the Weber options. You can mount downdraft Webers on the stock intake manifolds, with adapters. The 32/36 DGAVs were popular; I had these on my coupe when I bought it. For the b32, however, I would think a set of 38/38 DGAVs would be preferable.

Lastly, you can go with sidedraft Webers (either DCOEs or DCOMs). Usually, these are a fair bit more expensive. Not only would you be buying three carbs v. two, but you need different intake manifolds, and with these, you may run into issues with both the thermostat housing and with the brake booster.

I'm pretty sure I have a front timing cover and a distributor in you need them.
And for sidedrafts if you drive to higher elevations you'll have to re-jet every time you went/returned.
 

Ezz

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Post a pic of underside of head, are the two shallow dimples still present on intake side? If not it has been cut to minimum thickness. If they are there and you keep it, take it to a machinist to pressure test for cracks, if good then clean up valves, replace any bad valve guides and all valve stem seals. If you go b35 then use the b35 head as ports are larger and it has dual valve springs. The loose oil pipe screw might still be okay, if it fell off you would lose oil to the cam and rockers.
The oil screw was there just loose enough I could turn it with my fingers.

Here is the underside of the head with pics of the dimples, I think…
8F19BE04-F097-477F-A13A-87DD72453D54.jpeg


350A11CB-5E2A-431E-B0CA-657F99ECD272.jpeg



f you go b35 then use the b35 head as ports are larger and it has dual valve springs.
do mean the b35 head with the b32 block?

thanks!
 

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Ezz

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B32 update

I just noticed this on head and piston #1: obviously, it is outside the head gasket sealing area, but how bad is this? any hopes for the piston to be reused? head?
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day66

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Looks like it’s had some sort of foreign body through it! Personally I wouldn’t worry about the head, piston doesn’t look beyond use to me but I would be concerned about the state of the bores - it does look like it’s been standing with water in a couple of the cylinders so unless the marks hone out, I don’t think I’d but anymore time into the bottom end.
 
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Ezz

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Looks like it’s had some sort of foreign body through it! Personally I wouldn’t worry about the head, piston doesn’t look beyond use to me but I would be concerned about the state of the bores - it does look like it’s been standing with water in a couple of the cylinders so unless the marks hone out, I don’t think I’d but anymore time into the bottom end.

There is a lot of oil burned onto those valves which I think indicates piston ring issues.
I am planning on honing the cylinders and replacing the piston rings.
Any thoughts on how to know what stone grit I should use?
Thanks!
 

HB Chris

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I’ve never honed a cylinder so I can’t help there and it has been 45 years since I installed rings, I let the machinist do it!
 
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stphers

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Depends on whose rings that you are using. See what they recommend for a grit. I would only use a ball hone with lots of solvent as a lubricant. And to get a proper degree on the cross hatch, you have to go up and down with the hone pretty quickly, not slow Funny, just did a 74 tii 2002 block with my hone the other day, using Deves rings

Thanks, Rick
 

Ezz

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Depends on whose rings that you are using. See what they recommend for a grit. I would only use a ball hone with lots of solvent as a lubricant. And to get a proper degree on the cross hatch, you have to go up and down with the hone pretty quickly, not slow Funny, just did a 74 tii 2002 block with my hone the other day, using Deves rings

Thanks, Rick
Thanks Rick!
I will look up manufacturer for stone grit recommendation.

As this is a learning experience for me, i would like to know why you prefer the ball hone over the three stones hone?
Like this one:
 

Stevehose

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Cylinder honing is both thrilling and terrifying at the same time. I used a ball hone and lots of oil, I think I read soemwhere they are more forgiving than the tri-arm version above. Lots of good Utube videos showing technique.
 
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StephenZ

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Definitely the ball hone. I can't remember the grit of the one I did mine with, but like others have said, a nice brisk pace to get a good cross hatch. It wan't tough to do...a little nerve wracking at first..lol. Make sure you check for a ridge at the top of your cylinders before just throwing a hone on it, too.
 
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TodB

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I know TodB has one in his coupe and likes it a lot.
My ears are ringing :).

My B32 with dual weber 38s runs great. It was last dynoed at 165 HP at the wheels. The 123 dizzy really helped smooth things out which I thought were more carb/jet related. Pulls right up to redline with no issue. I'm certainly not going to win any stop light races, but its plenty peppy for a 50 year old car. Its a wonderful touring car which I'm about 10 minutes away from going our for my Sunday drive after I get my morning car fourm update!
 

bmw2800cs

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My ears are ringing :).

My B32 with dual weber 38s runs great. It was last dynoed at 165 HP at the wheels. The 123 dizzy really helped smooth things out which I thought were more carb/jet related. Pulls right up to redline with no issue. I'm certainly not going to win any stop light races, but its plenty peppy for a 50 year old car. Its a wonderful touring car which I'm about 10 minutes away from going our for my Sunday drive after I get my morning car fourm
Are your 38's downdraft or side? Progressive (I assume not)? I apologize in advance for asking noob questions.
 
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